In a small saucepan, boil the reserved marinade for 5 minutes, or until thickened to a glaze consistency.

Preheat a grill. When it is too hot to hold your hand six inches above the grill for more than 5 seconds, it's ready. Remove the steak from the marinade and season both sides with salt and pepper. Grill until medium rare to medium, about 4 minutes on each side. Let the steak rest for 5 minutes.

To serve, brush the reserved marinade over the steak and cut against the grain into thin slices. Serve warm.